Studies with gas filled kites conducted at the University of Mellencamp in Dearborn, Michigan showed that a high concentration of METHANE gas allowed the kites to perform in ways previously thought impossible.

New tricks, previously extremely difficult, became the norm.

Researchers connected tubes to the anuses of hundreds of cows and volunteer grad students to collect a substantial amount of a renewable gas supply which coincidentally also reduced the CO2 emissions from participants. An unexpected plus.

The study was abruptly terminated when a participant attempted to light up a big doobie and blew up the facility.

Helium is used for testing of pressure equipment, since it leaks faster than air and trough smaller holes, so you can detect very small lekages. So the first thing that should be tested is how good valves hold the pressure at 8 psi. If there are any small leakages in the blader (lets say your kite gets soft after 2 hours), one point inflation system connection points (specially Octopus) would leak out you kite in no time. I wonder if you could even come to 8 psi.
However I do not understand what should not be safe about helium?!